Bharmauria Vishal, Bachatene Lyes, Cattan Sarah, Chanauria Nayan, Rouat Jean, Molotchnikoff Stéphane
Neurophysiology of the Visual System, Département de Sciences Biologiques, Université de Montréal, CP 6128 Succursale centre-ville, Montréal, QC, H3C 3J7, Canada.
Département de Génie Électrique et Génie Informatique, Université de Sherbrooke, Sherbrooke, QC, Canada.
Eur J Neurosci. 2015 Jun;41(12):1587-96. doi: 10.1111/ejn.12912. Epub 2015 Apr 30.
Neuronal assemblies typically synchronise within the gamma oscillatory band (30-80 Hz) and are fundamental to information processing. Despite numerous investigations, the exact mechanisms and origins of gamma oscillations are yet to be known. Here, through multiunit recordings in the primary visual cortex of cats, we show that the strength of gamma power (20-40 and 60-80 Hz) is significantly stronger between the functionally connected units than between the unconnected units within an assembly. Furthermore, there is increased frequency coherence in the gamma band between the connected units than between the unconnected units. Finally, the higher gamma rhythms (60-80 Hz) are mostly linked to the fast-spiking neurons. These results led us to postulate that gamma oscillations are intrinsically generated between the connected units within cell assemblies (microcircuits) in relation to the stimulus within an emergent '50-ms temporal window of opportunity'.
神经元集群通常在伽马振荡频段（30 - 80赫兹）内同步，并且是信息处理的基础。尽管进行了大量研究，但伽马振荡的确切机制和起源仍不为人所知。在此，通过对猫的初级视觉皮层进行多单元记录，我们发现，在一个集群中，功能连接的单元之间的伽马功率（20 - 40赫兹和60 - 80赫兹）强度显著强于未连接的单元之间。此外，连接单元之间的伽马频段频率相干性高于未连接的单元之间。最后，较高的伽马节律（60 - 80赫兹）大多与快速放电神经元相关。这些结果使我们推测，伽马振荡是在细胞集群（微电路）内连接的单元之间，相对于一个出现的“50毫秒时间机遇窗口”内的刺激而内在产生的。
